Microsoft's chief executive search has been in full swing since Steve Ballmer announced his retirement in August, and the company has said it hopes to find a replacement by the end of 2013. Naturally, many names have popped up for the rumoured shortlist, including those of executives from Ford and Nokia, as well as from within Microsoft.

If the flurry of anonymous whispers and speculative reports are beginning to confuse you - scratch your head no longer. We've compiled a round-up of all the potential CEO candidates with brief summaries for each and why they might be in the running. We'll also update the list as new names are announced, and that includes if and when Microsoft finally names its next chief executive.

Remember, none of this information is Microsoft-confirmed. It's all based on circulating stories with unverified sources, though it is still interesting to conjecture.

Alan Mulally

Update: Alan Mulally has officially confirmed that he is staying at Ford at least until the end of 2014, quashing any suggestion that he is to take the Microsoft role. Speaking in an interview with the Associated Press, he said he would like to "end the Microsoft speculation" and that it had been a "distraction for Ford".

News emerged in September that Alan Mulally, CEO of Ford Motor Company, was in the lead to take the reins of Microsoft. A report by AllThingsD, which cited several unnamed sources, emphasised that Mulally had not entered formal negotiations, but that discussions with him at Microsoft were "serious".

Mulally owns a house in Seattle, which is near to Microsoft's headquarters, and lived there while serving as Boeing Commercial Airplanes' CEO. He purportedly often thinks about returning to the city. As well as being located near Microsoft, Mulally has strong and influential ties to the company - he advised Ballmer on its recent internal restructure, for instance.

That said, Bloomberg reported more recently that Mulally has become a less-likely candidate as of late. He has apparently faded as a leading candidate within the last few weeks because of his lack of technological experience. A Ford board member also said Mulally would remain with Ford until the end of 2014.

Stephen Elop

Stephen Elop, former CEO of Nokia Corporation and a former Microsoft executive, was considered a strong candidate very early on in the search, mostly because Microsoft chairman Bill Gates had acknowledged that Microsoft's board was interviewing both internal and external candidates.

Additionally, when Microsoft announced plans to buy Nokia in September, the company revealed that Elop would become the executive vice-president of the devices and services division.

Many reports have since claimed that Elop is mulling a strategy shift at Microsoft if he gets the CEO gig. This would involve capitalising on Microsoft Office by pushing it on rival iOS and Android platforms, but he is also reportedly willing to shut down or sell some major Microsoft businesses such as the Bing search engine and Xbox division.

However, Bloomberg reported in November that Microsoft’s board was no longer focusing on Elop. Although he supposedly remains a potential candidate, he is "less likely" to be offered the CEO position.

Satya Nadella

Somewhere along the way, Satya Nadella's name popped up in the search for Microsoft's next CEO. Bloomberg again weighed in, claiming that Microsoft's board is interested in the internal executive as a candidate. He is the current executive vice-president of Microsoft’s Cloud and Enterprise group.

Nadella recently spoke at the LeWeb conference for start-ups and Web entrepreneurs in Paris, where he addressed a question about the CEO search. Interviewer Om Malik asked Nadella what it was like to work at Microsoft while being a possible CEO candidate.

“For me, it’s a great time to be at Microsoft for what we’re doing. And day to day, it is about getting focused on what I’m doing and I’m excited to be doing that," responded Nadella, who, in a seperate interview with Bloomberg, also said he would stay at Microsoft no matter what happened with the CEO search.

Thus far, Nadella's name has not been crossed off the shortlist.

UPDATE: Microsoft's next CEO is Nadella, according to Bloomberg.

Recode, which also claimed Nadella will become CEO, said an official announcement will come from Microsoft within the next week. Nadella is reportedly being considered a strong choice because of his technical background and familiarity with Microsoft. He's been with the company since 1992.

Tony Bates

Insiders told AllThingsD that several tech leaders in Silicon Valley, as well as some top executives in Microsoft, want Tony Bates for CEO. He's the company's current executive vice-president of Microsoft responsible for Business Development, Strategy and Evangelism, having previously served as president of the Skype Division at Microsoft.

Sources claimed his past experience at Cisco was a huge draw, because he managed more than 12,000 global workers and helped bring in $20 billion in revenue. He also reportedly taught himself to code by reading programming manuals on the way to work and began his career as a network operator at the University of London.

The main drawback to having Bates as a CEO is that he has never led a company before, but neither has Nadella. Additionally, journalist Kara Swisher said he was "too friendly to the digerati, and a wee bit too interesting, too". Are those really considered negative qualities?

Kevin Turner

Bloomberg reported that Microsoft's board, as of early November, had apparently whittled down the list of internal candidates to a few people, one of whom was Kevin Turner, the chief operating officer of Microsoft.

He joined the company in 2005, from Wal-Mart Stores Inc. He was CEO of Sam’s Club, among other roles, in an 18-year career at the retailer.

Not much else has been said about Turner being in the running, but that's not too unusual considering his competition includes Silicon Valley favourites Bates and Nadella.

Steve Mollenkopf

Update: Qualcomm has announced that Mollenkopf has been promoted to the role of CEO at the company, quashing rumours that he's about to abscond to Redmond. We can now rule him out.

Microsoft is now looking at Steve Mollenkopf, the chief operating officer of Qualcomm, according to Bloomberg. He's been with the leading mobile chip manufacturer since 1994.

Qualcomm's success in mobile space is what makes Mollenkopf a prime candidate on the rumoured shortlist, especially because Microsoft still wants to push the Windows Phone platform as a strategy for the future.

Bloomberg also noted that Ballmer, during a presentation at Microsoft's most recent analyst day, mentioned Qualcomm as one of the few companies that had successfully taken advantage of the shift to mobile computing in the form of tablets and smartphones.

Ballmer's name drop, coupled with Mollenkopf's role as the second in command at Qualcomm, could support the wide array of rumours about Microsoft swaying from Mulally and Elop and considering other CEO candidates.

That's it - for now. Keep checking back for more candidate rumours, though. We'll update this article as the news breaks.